Displaying multiple CopLists at once

[Graham Humphrey]

Just at the beginning of a little project and I'm trying to get three CopLists on the screen at once, one is the main game area (coplist 0) and the other two are status panels which will contains score and lives info for the two players.

So I have:

InitCopList 0,60,224,$00005,8,32,0    ; main game display
InitCopList 1,44,12,$00005,8,32,0     ; p1 panel
InitCopList 2,288,12,$00005,8,32,0    ; p2 panel

Bitmap 0,320,224,5:Bitmap 1,320,224,5 ; main game display
Bitmap 2,320,16,5:Bitmap 3,320,16,5    ; panel displays

[Placeholder tile gfx blit onto bitmaps 0 and 1]
[Print "p1 test" and "p2 test" text onto bitmaps 2 and 3]

CreateDisplay 1,0,2

Repeat
 Vwait
 DisplayBitmap 0,db
 DisplayBitmap 1,2:DisplayBitmap 2,3
 db=1-db
 UnBuffer db
 Use Bitmap db
Until RawStatus($45):End

The main game area displays as expected, but for some reason I only seem to get the bottom CopList and not the top one. I NPrint text to both the bitmaps for CopLists 1 and 2, but they both appear on the bottom coplist and the top one is blank (and the second line of text is cut off as the CopList isn't high enough to display both properly).

Any ideas? On other projects, I can have two CopLists displaying fine, but any more than two and I run into problems

[Daedalus]

Hmmm... It sounds to me like you're actually printing the text to the same bitmap since the text is appearing below the other text - are you doing a BitmapOutput command before the first NPrint? Output will default to the last bitmap created unless you tell it otherwise.

If you pop out of Blitz mode (or initialise your bitmaps in Amiga mode), you can save the bitmaps to RAM: in order to see if they really contain what you expect:

SaveBitmap 0, "RAM:bitmap0.iff"
SaveBitmap 1, "RAM:bitmap1.iff"
Delay_ 50 ; Just to let file access finish before shutting down multitasking.

I can't remember using 3 coplists myself, but the code *looks* fine to me.

[idrougge]

Not that it has anything to do with your NPrint problem (which Daedalus points out above), but I think you need a few blank lines between your coplists.

[Graham Humphrey]

Thanks chaps for the help.

Well, what do you know - it was the BitmapOutput command. What I was doing was using BitmapOutput on both bitmaps 2 and 3, and then using Use Bitmap before using NPrint, but that had no effect - the last bitmap referenced for BitmapOutput was 3, so all text was printed to that.

The reason I came to the conclusion I initially did (which was mad, I know) is that I've experimented with multiple CopLists in the past and always had problems getting them to display properly (not text-wise, just in general), so I automatically thought I was missing something. As idrougge points out, on those occasions it might well have been too few blank lines between CopLists but I took care on this occasion to ensure there was a gap of four lines between each one.

Anyway, up and running now, so a big thanks to you both for putting me on the right track

[idrougge]

Originally Posted by Graham Humphrey

As idrougge points out, on those occasions it might well have been too few blank lines between CopLists but I took care on this occasion to ensure there was a gap of four lines between each one.

It's been to long since I made a coplist-based Display, I didn't notice that you specified the panels to be only 12 pixels high.